Required task inputs fail at runtime instead of validation (Build.dockerfile/tags, Stop.containerId)

Inspect src/main/java/io/kestra/plugin/docker/cli/Build.java around the dockerfile and tags fields and their use in run(), then inspect Stop.java around containerId and its run() method. Confirm that missing or empty required inputs fail validation and that containerId appears in the main group instead of connection.

Describe the issue

plugin-docker

Build: dockerfile and tags can fail at runtime instead of validation

Summary
Build derives required inputs without null/empty validation, so bad input throws a raw exception at execution time rather than failing flow validation up front.

Location — src/main/java/io/kestra/plugin/docker/cli/Build.java

• dockerfile field (~L157) has no @NotNull, but run() calls runContext.render(this.dockerfile)...orElseThrow() (~L258).
• tags is @NotNull (guards null, not empty), and run() calls tags.iterator().next() (~L251) to derive the registry.

Impact

• Omitting dockerfile passes validation, then throws NoSuchElementException/orElseThrow at runtime.
• An empty tags: [] passes @NotNull, then throws NoSuchElementException.

Suggested fix
Add @NotNull to dockerfile (or validate before use) and @NotEmpty/@Size(min = 1) to tags.

Stop: containerId lacks @NotNull and is mis-grouped

Summary
containerId is the required primary input but is neither validated nor grouped as such.

Location — src/main/java/io/kestra/plugin/docker/cli/Stop.java

• containerId (~L59-64) is @PluginProperty(group = "connection") with no @NotNull.
• run() calls ...containerId...orElseThrow() (~L88-94).

Impact
Omitting containerId throws a raw NoSuchElementException at runtime instead of failing validation; the property also renders under "connection" instead of "main" in the UI.

Suggested fix
Add @NotNull and move it to group = "main".

Environment

• Kestra Version: rc10
• Latest plugin version